Laminar flow elbow systems and methods are known for which a pipe section comprising a substantially straight pipe section defines a flow path for fluid, and said straight pipe section is adapted for inclusion prior to a curved pipe section, such as a 90.degree. elbow, and which straight pipe section includes a plurality of vanes therein as a means for imparting rotation of said fluid before passing through the curved pipe section, and typically with said fluid rotation imparting means being fixed within said straight pipe section. The plurality of vanes within the straight pipe section which composes the rotation imparting means typically is designed to impart sufficient rotation to the fluid to minimize turbulence and flow maldistribution as it passes through the curved pipe section, while insuring that the fluid rotation substantially terminates upon exiting from the curved pipe section. Typically, the pre-elbow pipe section is straight and circular, and the elbow pipe section has an inclusion angle and a turning radius with the turning vane curvature employed in the rotation-imparting means having a maximum angle Theta proximal to the pre-elbow pipe section wall. The Theta angle is approximately equal to 1/4 of the pre-elbow pipe sections in internal diameter, multiplied by the inclusion angle and divided by the turning radius, thereby turbulence and flow maldistribution are minimized as fluid flows through the pipe elbow. Such laminar flow elbow systems and methods are described, for example, in U.S. Pat. No. 5,197,509, issued Mar. 30, 1993, hereby incorporated by reference in its entirety.
It is desired to provide for a new and improved laminar flow elbow system and method or means for imparting forward and backward rotation to a fluid passing through a defined flow path and through straight and curved pipe sections through a system to overcome certain disadvantages found in such prior art systems. It is also desirable to provide for a fluid rotation-imparting means such as a pipe section having a plurality of vanes which provide certain operating, functional, and manufacturing cost and efficiency advantages not present in the prior art.